Damgaard C., Strandberg B., Nielsen, K.E., Bak J. & Skov F. 2007. NERI Technical Report no. 637. 48 pp.

 

 

 

Summary

With the implementation of the habitat directive, which primarily is a management directive, the management of natural habitats will receive more attention. Based on literature and management experience suggestions for management strategies are reported in order to reduce the impact of nitrogen. For some habitat types, e.g. natural forests and raised bogs, there are no known management strategies that will diminish the nitrogen content. Since management data are unevenly distributed among the different habitat types, this report will focus on the open habitat types such as heathlands and dune systems since most management data come from such habitat types.

In the initial project phase there was a workshop on different management strategies (Workshop om Forvaltningsmetoder i N-belastede habitatnaturtyper, Gjern Søhøjland 19-20 April 2006) in order to collect practical experience. The presentations, in Danish are available at the webpage of By- og Landskabsstyrelsen.

The purpose of the report was two-fold:

1.       To collect experience on management strategies, which were assembled in the former Danish counties.   

2.       To describe models and assumptions necessary for predicting the effect of different management strategies on nitrogen pools in natural habitats and on plant community dynamics.        

In the report it is suggested i) to measure the nitrogen pool in specific areas relevant for management and ii) to use mathematical models to understand and predict the effect of different management strategies on the development of the nitrogen pool and plant community dynamics.

In the report emphasis is on a quantitative description of the considerable uncertainty that exists on the effects of different management strategies for removing nitrogen. However, it was not possible to formally estimate the uncertainty due to lack of homogenous data, and instead an expert assessment of the degree of uncertainty was performed.

Expert assessment on the removal of nitrogen from natural habitats with different management strategies.

 

 

 

 

	Unit	Average	Distribution
Denitrification	kg/ha/year	wet heath: 1,5 dry heath : 0,15	wet heath : uniform (min = 1; max = 3) dry heath : uniform (min = 0; max = 0,3)
Leaching	kg/ha/year	1,2	95% uniform (min = 0; max = 1) + 5% uniform (min = 1; max = 30)
Cutting	kg/ha	116,7	triangle: (min = 50;  modus = 100; max = 200)
Burning	kg/ha	116,7	triangle: (min = 50;  modus = 100; max = 200)
Removal of peat	kg/ha	1166,7	triangle: (min = 500;  modus = 1000; max = 2000)
Grazing	kg/ha	10	uniform: (min = 5; max = 15)

 

 

 

 

 

 

 

 

 

 

 

 

 

Full report in pdf-format (707 kB)